Compacting press



May 12, 1964 E. v. CRANE 3,132,379

COMPACTING PRESS Filed April 12. 1961 5 Sheets-Sheet 1 INVENTOR. fi-EDWARD "v. CRANE ATTQRNEYS May 12, 1964 E. v. CRANE COMPACTING PRESS 5Sheets-Sheet 2 Filed April 12, 1961 INVENTOR. EDWARD v. CRANE BY MQMJkATTORNEYS May 12, 1964 E. v. CRANE 3,132,379 COMPACTING PRESS IINVENTOR. EDWARD V. CRANE May 12, 1964 E. v. CRANE 3,132,379

COMPACTING PRESS Filed April 12, 1961 v 5 Sheets-Sheet 4 INVENTOR.EDWARD V. CRANE A TORNEYS May 12, 1964 E. v. CRANE COMPACTING PRESSFiled April 12, 1961 5 Sheets-Sheet 5 INVENTOR. EDWARD V. CRANE Assu-.uw i m ATTOR N EYS United States Patent 3,132,379 COMPACTHIG PRESSEdward V. Crane, Qanton, Ohio, assignor to E. W. Bliss Company, Canton,Ohio Filed Apr. 12, 1961, Ser. No. 192,556

7 Claims. (Cl. 18-165) This invention relates to press apparatus forcompacting metal powders and the like, aswell as to means forautomatically lubricating the compacting punch, die and mandrel for suchpresses.

As an overall object, the present invention seeks to provide a new andimproved compacting press capable of producing an improved product at ahigher production rate than previously known presses of this type.

As the name implies, a compacting press of the type described herein isadapted for use in compacting metal powder to produce slugs which aresubsequently sintered and employed, for example, as billets in an impactextrusion operation. In order to produce compacts of as uniform densityas is practical, it is desirable to provide a press having a floatingdie which moves downwardly at about half the speed of the punch duringthe compacting operation, the reason being to produce the uniformdensity desired. In addition, it is necessary to provide means forejecting the compacted mass out of the die at the completion of thecompacting operation. As will be seen, the present invention provides ahydro-pneumatic mechanism for controlling the movements of the die andthe ejector mechanism without requiring complicated mechanical movementsfor accomplishing these functions. At the same time, the hydro-pneumaticmechanism facilitates a higher production rate not easily attainable bythe use of amechanical movement.

Another object of the invention is to provide'means for lubricating thedie walls and mandrel of a powder compacting press.

In the compacting operation, particularly at high production rates, alarge amount of heat is generated which, in the absence of a lubricant,causes the powder to adhere to the die walls and mandrel. in order tosuccessfully compact powder and eject the compacted slug from the die,it has usually been considered necessary to mix the powder with alubricant to aid in ejection and to produce a more uniform density overthe length of the slug. Examples of such lubricants which have beenmixed with the powder are zinc stearate, lithium stearate, or stearicacid. The addition of lubricants to the powder, however, presentscertain difliculties. Some difliculty is encountered in uniformly mixingthe powder with the lubricant while avoiding lumps or localconcentrations. In addition, a residue of the lubricant, or its ashinclusions in the final product is a source of local weakness orobjectional splitting.

In the present invention, in contrast to previous procedures, the powderto be compacted need not be mixed with a lubricant. :Rather, the wallsof the die and mandrel are automatically swabbed with a lubricant aftereach compacting operation, thereby producing the desired lubricatingeffect while avoiding the undesirable effects produced by mixing alubricant throughout the powder.

In accordance with one aspect of the invention, a compacting press isprovided comprising a vertically reciprocable die which receives powderto be compacted, a punch which is forced into the upper end of the die,and an ejector plunger having its upper end extending into the lower endof the die. During a compacting operation, the lower end of ejectorplunger is seated against a supporting mem her and provides a rigidsurface against which powder is compacted. This ejector plunger isconnected to a piston reciprocable within an outer hydraulic cylinderwhich Patented May 12, 1964 is connected to the punch through connectingrods, the arrangement being such that when the punch moves downwardly,the hydraulic cylinder will move downwardly also; however, the pistonand ejector plunger will remain seated against the aforesaid supportingmember to provide the necessary surface against which powder iscompacted. At the same time, the reciprocable die is connected throughtelescoping air cylinders to the aforesaid piston whereby the die willfloat downwardly while compressing air within the telescoping aircylinders. By permitting a fluid to flow through a check valve to thelower end of the aforesaid hydraulic cylinder during the downward strokeof the punch, the fluid will be entrapped within the lower end of thecylinder during the upward stroke to force the piston and ejectorplunger upwardly and thereby eject a cornpacted mass out of the diewhile the air cylinders return the die to its original uppermoststarting position. The cycle is completed by opening a valve to permitfluid to flow out of the bottom of the hydraulic cylinder while the aircylinders force the aforesaidpiston and ejector plunger downwardly whilefilling the die with a new charge of powder to be compacted.

In accordance with another feature of the invention, the aforesaidejector plunger is provided with an axiallyextending passageway throughwhich a mandrel extends, this mandrel serving to form a core in thecompacted slug. By providing radial holes between the passage in theplunger and its outer peripheral surface, and by injecting a lubricantinto the passageway in the ejector plunger in timed relationship withthe portion of the cycle when the ejector plunger begins its downwardstroke to fill the die with a new charge of powder, the lubricant willflow out through the radial holes and be swabbed onto the walls of thedie as the plunger moves downwardly. At the same time, the lubricantwill be swabbed onto the mandrel, thereby making it unnecessary to mixthepowder with a lubricant, a procedure which is undesirable for thereasons pointed out above.

The above and other objects and features of the invention will becomeapparent from the following detailed description taken inconnection-with the accompanying drawings which form a part of thisspecification and, in which:

FIGURE 1 is a cross-sectional view of the compacting tools andhydro-pneumatic means of this invention showing its working parts in thepositions they occupy after the die has been tilled with powder, butbefore the punch is brought down into the die to compact'the powdertherein;

FIGURE 2 is a cross-sectional view similar to that of FIGURE 1, butshowing the working parts in the positions they occupy during thecompacting stroke of the ap paratus;

FIGURE 3 is another cross-sectional view similar to that of FIGURES 1and 2, but showing the working parts in the positions they occupy when acompacted slug is ejected from the die;

FIGURE 4 is a partially broken-away view of the powder fee-dingmechanism;

FIGURE 5 is an enlarged view of the ejector plunger, the mandrel and thedie of the invention, showing the manner in which a lubricant is swabbedonto the surfaces of the die and mandrel; and,

FIGURE 6 is a schematic illustration of one type of control system whichmay be used with the compaction apparatus of this invention.

Referring now to FIGURES 1, 2 and 3, and particularly to FIGURE 1, thegeneral organization of the press includes a bolster plate 10 which issupported by bed frame members, not shown, as at 12 and 14-. Supportedon the bolster plate 10 is'the die holder 18. As shown, the die holder18 is provided with a central aperture 20 which receives an annular orcylindrical member 22 having threads provided on its outer periphery,the member being secured to block 18 by means of bolts 21. Above thecylindrical member 22 is a second cylindrical member or annular nut 28which supports, on its upper surface, a die table 30. The die table 30is provided with an annular ring 32 having a flange 34 which isinterlocked with a cooperating flange 36 on the upper edge of nut 28,the arrangement being such that the nut 28 may be rotated to raise orlower the die table without rotating the die table itself.

Provided in the die table 30 is a centrally disposed bore 38.Surrounding the lower edge of bore 38 is a bushing 40 which is fastenedto the die table 30 as by means of bolts 42. Reciprocably receivedwithin the bore 38 and bushing 40 is a die block 44 surrounded by anannular member 46 which is slideable on the inner surface or periphery48 of the cylindrical member 22. Member 46 is secured to the die block44 between shoulder 50 and an annular ring 52 which is secured to member46 by means of bolts 54. Formed on the inner periphery, or wall 48 ofthe cylindrical member 22, there may be provided a keyway 56 whichslidably receives a key 58 located in the annular member 46. The key 58and the keyway 56 are not, however, required, and may be omitted ifdesired. With this arrangement, the entire assembly of die block 44,member 46, and the ring 52 may reciprocate within the cylindricalmembers 22 and 40. As the assembly moves downwardly, for example, theupper reduced diameter portion of the die block 44 will slide on theinner periphery of bore 38 and bushing 40; while the annular member 46will slide on the inner periphery 48 of cylindrical member 22.

The die block 44 has a centrally disposed bore 60 extendingtherethrough; and this bore receives, at its lower end, an ejectorplunger 62. In its lowermost position, shown in FIGURE 1, the ejectorplunger 62 is seated on the bolster plate 10 as at 64 whereby its uppercup shaped end 66 Will act as a floor against which powder is compacted.Extending through the ejector plunger 62 is a centrally disposed mandrel68 which serves to form a core in the compacted slug as will hereinafterbe explained. At its lower extremity the mandrel 68 is threaded into arod 70 which, in turn, is threaded into a horizontally-extending plateor member 72. Secured to the plate 72 are four circumferentially spacedrods, only two of which are shown in FIGURES 1, 2 and 3, and identifiedby the numerals 74 and 76. These rods contact the lower surface of theannular member 46 of the die as sembly whereby the entire die assemblyof elements 44, 46 and 52 will reciprocate with the mandrel rod 68 andthe plate 72 as a unit.

Disposed above the bore 60 in die block 44 is a punch 78 having an axialbore 80 therein which receives the mandrel rod 68 during a compactingoperation. The punch 78 is carried on a punch plate 82 by means of anannular ring 84, substantially as shown. The punch 78 has a cup shapedaperture 79 which is similar to the cup shaped end 66 of the ejectorplunger 62. The cup shaped aperture 79 of the punch cooperates with thecup shaped end 66 of the ejector plunger to form a compact or slug Cwhich has beveled upper and lower edges, as shown in FIGURE 3. Thebeveled edges tend to minimize the effect of, and in some instances mayprevent the distortion of the edges of the slug during subsequenthandling and treatment of the slug. For example, if the slug were formedwith square edges, distortion of the edges during sintering may produceburrs or projections extending from the slug. These edge defects mayinterfere with the feeding of the slug into an extrusion die.

Threaded into the punch plate 82 and depending downwardly therefrom area pair of rods 88 and 90 which extend through openings provided in theplate 18, the bolster block 10 and the horizontal plate 72. These rodsare connected at their lower extremities to a horizontal cross member 92which supports a hydraulic cylinder 94 surrounded by a cylindricalmember 96 which forms an annular oil reservoir 98 between the innerperiphery of member 96 and the outer periphery of the cylinder 94.Communicating with the cylinder 94 of a bore 100 in cross member 92, thebore being provided at its bottom end with a closure plate 102 which isbolted to the cross member.

Received within the cylinder 94 is a piston member 104 which isconnected through a pair of rods 106 to the ejector plunger 62, thearrangement being such that as the piston member 104 moves upwardly, theejector plunger will be forced upwardly also to eject a compacted massout of the bore 60. Only one of the rods 106 is shown in FIGURES 1, 2and 3. One of these rods lies behind the pin 70 while the other rod liesin front of the pin, as will be understood.

Positioned on top of the piston member 104 is a horizontal plate 105.Carried on this plate in depending relationship is a cylindrical skirt108 which carries, at its lower extremity, an annular ring 110. Betweenring 110 and the horizontal plate 72 are a pair of air cylinders 112 and114, each of which comprises a pair of telescoping parts 116 and 118.The telescoping parts 116 and 118 are sealed such that when member 116moves downwardly into member 118, for example, the air within thecylinder will be compressed.

A piston ring 222 is located between the inner surface of skirt 108 andthe outer periphery of member 96. A port 224 (see FIG. 2) formed in theskirt 108 communicates by means of conduit 228 with a choke 230 and acheck valve 226. The check valve 226 is connected to permit theadmission of atmospheric air into the space confined between the lowersurface of plate "105 and the top of annular cylinder 94 within skirt108. Piston ring 222 acts as a seal against the passage of air outwardlybetween the skirt 108 and the outer periphery of member 96, therebypermitting the escape of air from this space to be controlled by thechoke 230. In this manner, the dashpot action of the piston ring 222 maybe controlled to cushion the downward movement of the ejector.

Connecting the bore 100 and the lower end of cylinder 94 to the bottomof reservoir 98 is a conduit 120 having a check valve 122 therein whichpermits liquid to flow from the reservoir into the bottom of cylinder 94while preventing the return of liquid into the reservoir from thecylinder. In shunt with check valve 122 is a pressure relief valve 124and a controlled valve 126 which is operated by means of an air cylinder128. When the punch 78, punch plate 80, cross member 92, and cylinder 94move downwardly to expand the chamber below piston member 104, the checkvalve 122 will open to permit liquid to flow from reservoir 98 to thebottom of the cylinder. However, on the upward stroke of the punch, thecheck valve 122 will prevent the return of liquid into the reservoir,meaning that the piston member 104, rods 106, and the ejector plunger 62will be forced upwardly. Pressure relief valve 124 serves to limit theupward pressure to provide protection in case of a binding action or thelike on ejector 62. In order, then, to return the piston member 104 toits position shown in FIGURE 1, the valve 126 must be opened by aircylinder 128 to permit the liquid at the lower end of cylinder 94 toflow back into the reservoir 98.

Referring now to FIGURE 4, the powder feed mech' anism of the press isshown, it being understood that this mechanism extends transversely withrespect to the press structure as shown in FIGURES 1, 2 and 3. Itcomprises a pneumatic cylinder 130 which is connected through a pistonrod 132 to a feed carriage 134. Formed in the lefthand portion of thefeed carriage 134, as shown in FIG- URE 4, is a bore 136 adapted toregister with a delivery tube 138 which leads to a metal powder storagebin, not shown. The lower end of the feed tube 133 fits over acylindrical member 149 which is welded or otherwise se-,

curely fastened to a bracket 142. The bracket 142, in turn, is supportedby means of threaded connector studs 144 and 146 to the die table 31).Below the bracket 142 is an annular member 143 having a seal 150provided in its lower edge which engages the surface of the feedcarriage 134. This member 148 is forced downwardly against the uppersurface of the feed carriage by means of springs 152 interposed betweenthe bracket 142 and the member 148, the arrangement being such thatsufiicient pressure will be exerted on the seal 150 to restrain powderfrom being spread over the upper surface of the feed carriage 134.

Depending downwardly from the left-hand end of the feed carriage 134,and concentric with the bore 136, is an annular flange 154. Surroundingthis flange is a ring member 156 which, like member 148, has in itsbottom surface a seal 158 which rides on the upper surface of the dietable 30. Interposed between ring member 156 and the feed carriage 134are coil springs 16% which serve to force the member 156 and the seal158 into engagement with the die table 30 and restrain powder from beingspread over the table. 7

With the arrangement shown, the cylinder 130 may be actuated to move thefeed carriage 134 to the right as shown in FIGURE 4, until bore 136registers with the bottom of feed tube 138. At this point, the powder inthe feed tube 138 will flow into the central cavity 162 formed by flange154 and ring member 156. Thereafter, the cylinder 130 will be actuatedto move the feed table 134 to the left as shown in FIGURE 4 whereby thecavity 162 will be positioned over the bore 60 in die block 44 such thatthe powder may be drawn into the bore by down ward movement of ejectorplunger 62 preparatory to a compacting operation.

Referring now to FIGURE 5, the ejector plunger 62 is provided with anaxially-extending inner bore 164 through which the mandrel rod 68extends. As shown, the main portion of the bore 164 has a diametersubstantially larger than that of the mandrel rod 63 to provide anannular passageway around the mandrel. This passageway is connectedthrough hole 166 to a flexible hose, not shown, which is adapted todeliver alubricant to the bore 164. O-rings 168 seal the lower end ofthe annular passageway to prevent leakage from the bottom of the bore.Clearance between the ejector and the mandrel rod 68 at 170 permitslubricant to be forced up into that area and out through radial holes172 onto the surface of bore 61) between the ejector plunger and thedie. An O-ring174 prevents the escape of this lubricant to the bottom.

When the ejector plunger 62 is at top stroke, a shot of lubricant isinjected through hole 166 into the passageway formed between the wall ofbore 164 and mandrel rod 68, thereby forcing the lubricant out throughradial holes 172 and onto the peripheral surface of bore 61 At thattime, the ejector plunger 62 is forced downwardly by the air cylinders112 and 114. This downward movement of the plunger wipes lubricant onthe walls of both the mandrel rod 68 and the bore 60, and at the sametime draws the next charge of powder into the die for compacting. Thus,with this method, it becomes unnecessary to mix a lubricant with thepowder before compacting since the lubricant is automatically suppliedto the die and mandrel during each compacting cycle.

Referring again to FIGURE 1, the positions of the parts of the pressshown are those which they will occupyjust before the punch 78 is forceddown into the bore 60 to effect a compacting operation. At this point,powder P will have been charged into the bore by the powder feedmechanism shown in FIGURE 4. The punch plate 82 and punch 78 are forceddownwardly into bore 60 by means of a conventional crankshaft-typepress, not shown. In this process, the rods 88 and 90 as well as thecross member 92 will be forced downwardly also, thereby pulling thecylinder 94 and reservoir 93 along with it. The

plate 195, rods 106 and ring 110, however, cannot move the cylinder 94,the check valve 122 will open to permit liquid to flow from reservoir 98into the bottom of the cylinder 94. At the same time, due to thefriction between the powdered metal which is being compacted by thepunch 78, and the die block 44, as well as mandrel-68, the entireassembly of the die block, the members 46 and 52, and the mandrel 68will float downwardly with horizontal plate 72 while compressing the airwithin cylinders 112 and 114. This is shown in FIGURE 2 where it can beseen that the plate 72 as well as the die assembly has moved downwardly.Plate 72 moves downwardly on rods 88 and 99, while the die assemblymoves downwardly on the surfaces of bore 38 and flange 40' as well asthe inner peripheral surface 48 of cylindrical member 22. At the sametime, the members'116 and 118 of each air cylinder 112 and 114 havetelescoped to thereby compress the air within the cylinders. Also, thespace between the lower end of piston 134 and the plate 102 hasincreased, and this space is filled with oil flowing through the checkvalve from reservoir 98.

When punch 78 reaches itslowermost position and begins its upwardstroke, the compacting operation will have been completed with thepowder being compacted against the upper surface 66 'of ejector plunger62 which did not move downwardly. As the punch 78 and rods 88 and 99move upwardly, they will carry with them the cross members 92 and thecylinder 94. Since, however, the oil at the bottom of cylinder 94 is nowtrapped by the check valve 122, the piston 104 must move upwardly also,and this upward movement of the piston carries with it the plate 195,the ring 1141 and the rods 106 which are connected to the ejectorplunger 62. As the ejector plunger moves upwardly, it will force thecompacted mass out of bore 60'; and, simultaneously, the upward movementof ring 110 will force the air cylinders 112 and 114 up wardly. In thisprocess, the plate 72 as well as the entire die assembly are also forcedupwardly into their original positions which they assumed at the startof the cycle.

The pressure relief valve 124 will prevent an excessive I buildup ofpressure beneath the piston 154 due to any binding or to reaching thestop position of the ejector plunger 62.

The positions of the parts of the press when the ejector plunger reachesits uppermost position are shown in FIGURE 3. At this point, the aircylinders 112 and 114 will be fully telescoped and the air within thesecylinders will be at maximum pressure since the piston 194 has beenforced upwardly by the column of oil in cylinder 94 beneath the piston.At this point, the compacted slug C will have been ejected out of bore60. Thereafter, the cylinder shown in FIGURE 4 is pressurized to movethe feed carriage 134 over the bore 61), thereby pushing the previouslycompacted slug C olf of the die table 36 and positioning the cavity 162over the bore 61). After the cavity 162 is positioned over the bore, thevalve 126 is opened by air cylinder 128 to permit oil to flow from thebottom of cylinder 94 back into reservoir 98, thereby permitting the aircylinders 112 and 114 to force the piston 104 and the ejector plunger 62downwardly until its lower surface seats'against the bolster plate 10 at64. Just before the ejector plunger 62 moves downwardly, a lubricant isinjected into bore 164 and is forced through radial passages 172 ontothe peripheral surface of bore 61 as well as onto the surface of mandrelrod 60. Thus, asthe ejector plunger 62 moves downwardly, a lubricantsuch as a solution of zinc stearate in benzene, is swabbed onto thesurfaces of these two members. Simultaneously, a new charge of powder isdrawn into the bore 69 preparatory to the succeeding compactingoperation.

When the ejector plunger 62 reaches its lowermost position, thecylinder13i will be pressurized to move the feed carriage 134 out ofregistry with the bore 60 Whereby the punch 78 may be forced downwardlyinto the bore to start a new cycle of operation. The height of thecolumn of powder charged into bore 60 may be adjusted by turning thelarge annular nut 28 to raise or lower the die table 30.

Control apparatus for effecting the foregoing functions is shown inFIGURE 6, it being understood that the particular control apparatusdisclosed herein is for purposes of illustration only, and that othertypes of control systems may be employed to etfect the same results.

Referring to FIGURE 6, when the punch plate 82 reaches its uppermostposition, it will close a limit switch 180 which will energize asolenoid 182 through timer circuitry 184 to open valve 186, therebypressurizing cylinder 130 to force the feed carriage 134 to the leftwhereby it will be positioned over the die. At the same time, the timer184 will energize the solenoid 190 to close contacts 192; however, thesecontacts will not be closed until after the feed carriage 134 has movedto the left.

When the feed carriage 134 is positioned over the die, it will trip alimit switch 194 which will energize solenoid 196 to open valve 198whereby air pressure will be admitted to cylinder 128 to open valve 126,thereby permitting oil to flow from the bottom of cylinder 94 toreservoir 98, whereupon the piston 104 and ejector plunger 62 movedownwardly to draw a new charge of powder into the die. When the limitswitch 194 closes, it also energizes solenoid 200 to open valve 202whereby air cylinder 204 is pressurized to inject a lubricant into theejector plunger 62 by means of piston pump 206, this pump beingconnected to a source of a lubricant, not shown. Thus, as the ejectorplunger 62 moves downwardly, a lubricant will be swabbed onto the wallsof the die as well as the mandrel 68.

After the die has been filled with a new charge of powder and the diewalls and mandrel swabbed with lubricant, the timer 184 will deenergizethe solenoid 182 whereby the valve 186 will pressurize the cylinder 130to move the feed carriage 134 to the right. As carriage 134 moves to theright, limit switch 194 is opened to close valves 198 and 202 wherebythe springs provided in cylinders 128 and 204 will force theirassociated pistons to their original positions. When feed carriage 134reaches its extreme right position, it will close limit switch 208, andsince solenoid 190 is energized and contacts 192 are closed at this timeby the timer 184, the solenoid 210 will be energized to open valve 212and engage a pneumatic clutch 214. The clutch 214, in turn, serves toconnect a motor 216 to a crankshaft 218 which is connected to the punchplate 82 through connecting rod 220. The clutch 214 is such that when itengages it will rotate the crankshaft 218 through one completerevolution and stop. In this process, the powder within the die iscompacted and at the completion of 360 of revolution of the crankshaft218, the limit switch 180 is again closed to repeat the cycle.

The present invention thus provides a compacting press in which nocomplex mechanical movement is required to acuate the die and othermoving parts of the device, which has a very high production rate, andwhich automatically provides for lubrication of the die and mandrelwithout requiring mixing of a lubricant with the powder and itsattendant difliculties.

Although the invention has been shown in connection with a certainspecific embodiment, it will be readily apparent to those skilled in theart that various changes in form and arrangement of parts may be made tosuit requirements without departing from the spirit and scope of theinvention.

I claim:

1. A compacting press for metal powders and the like comprising avertically reciprocable die having a vertical bore extendingtherethrough for the reception of a powder -to be compacted, avertically reciprocable punch adapted to be forced into the upper end ofsaid bore, an ejector plunger having its upper end extending into thelower end of said bore to provide a bottom surface against which powderis compacted, means for limiting downward movement of the ejectorplunger beyond a point where its upper end extends into the bore,hydraulic cylinder means for moving said ejector plunger upwardly fromsaid point into the bore at the completion of a compacting operation toforce a compacted mass out of the top of the bore,'said hydrauliccylinder means having an outer cylinder closed at its bottom and open atits top, means connecting said outer cylinder to said punch whereby itwill reciprocate with the punch, a piston member received within theopen top end of said outer cylinder and reciprocable therein above acolumn of substantially noncompressible fluid, means connecting saidpiston member to the ejector plunger, means for increasing the volume ofsaid column of non-compressible fluid when the punch and outer cylindermove downwardly, means for preventing the volume of said column ofnon-compressible fluid from decreasing when said punch and outercylinder move upwardly, and means including telescoping cylinderscontaining a compressible fluid connecting said piston member to thedie.

2. A compacting press for metal powders and the like comprising avertically reciprocable die having a vertical bore extendingtherethrough for the reception of a powder to be compacted, a verticallyreciprocable crankdriven punch adapted to be forced into the upper endof said bore, an ejector plunger having its upper end extending into thelower end of said bore to provide a bottom surface against which powderis compacted, means for limiting downward movement of the ejectorplunger beyond a point where its upper end extends into the bore,hydraulic cylinder means for moving said ejector plunger upwardly fromsaid point into the bore at the completion of a compacting operation toforce a compacted mass out of the top of the bore, said hydrauliccylinder means comprising an outer cylinder connected to said punch andreciprocable therewith, a piston member reciprocable within said outercylinder and connected to said ejector plunger, a liquid reservoir,check valve means connecting the liquid reservoir to the bottom of saidouter cylinder whereby liquid will flow from the reservoir to the bottomof the cylinder as the cylinder and punch move downwardly, andpre-pressurized, two-piece, telescoping air cylinder interposed betweensaid piston member and said vertically reciprocable die, whereby saidcylinder is compressed during the compacting action of said punch topermit said die to shift downwardly, and said cylinder is expanded toshift said die upwardly when said punch withdraws from said die.

3. A compacting press for metal powders and the like comprising a diehaving a vertical bore extending therethrough for the reception of apowder to be compacted, a vertically reciprocable punch adapted to beforced into the upper end of said bore, an ejector plunger having itsupper end extending into the lower end of said bore to provide a bottomsurface against which powder is compacted, means for limiting downwardmovement of the ejector plunger beyond a point where its upper endextends into the bore, means for cushioning the downward movement ofsaid ejector, hydraulic cylinder means for moving said ejector plungerupwardly from said point into the bore at the completion of a compactingoperation to force a compacted mass out of the top of the bore, saidhydraulic cylinder means comprising an outer cylinder connected to saidpunch and reciprocable therewith, a piston member reciprocable withinsaid outer cylinder and connected to said ejector plunger, a liquidreservoir, check valve means connecting said liquid reservoir to thebottom of said outer cylinder whereby liquid will fiow from thereservoir into the bottom of the outer cylinder on the downward strokeof said punch and said outer cylinder,

said check valve means serving to prevent liquid from flowing from thelower end of the outer cylinder to said reservoir on the upward strokeof said punch whereby the piston member and ejector plunger will beforced upwardly to eject a compacted mass out of said bore, powderloading means including powder delivery tube means; powder receivingmeans adapted to be shiftably positioned beneath said powder deliverytube means to receive a charge of powder therefrom; and cranksynchronized means to shift said powder receiving means from beneathsaid powder delivery tube means to pass over and center on said die boreafter a compacted mass has been ejected therefrom, and a valve deviceoperable when said powder loading means is over the top of said bore forpermitting liquid to flow from the lower end of said outer cylinder tosaid reservoir, the arrangement being such that when said valve deviceopens the piston member and ejector plunger will move downwardly tocharge said bore with a new supply of powder to be compacted.

4. A compacting press for metal powders and the like comprising avertically reciprocable die having a Vertical bore extendingtherethrough for the reception of a powder to be compacted, a verticallyreciprocable punch adapted to be forced into the upper end of said bore,ejector plunger having its upper end extending into the lower end ofsaid bore to provide a bottom surface against which powder is compacted,means for limiting downward movement of the ejector plunger beyond apoint Where its upper end extends into the bore, hydraulic cylindermeans for moving said ejector plunger upwardly into the bore at thecompletion of a compacting operation to force a compacted mass out ofthe top of the bore, said hydraulic cylinder means comprising an outercylinder connected to said punch and reciprocable therewith, a pistonmember reciprocable within said outer cylinder and connected to saidejecting plunger, a liquid reservoir, check valve means connecting saidliquid reservoir to the bottom of said outer cylinder whereby liquidwill flow from the reservoir to the bottom of the cylinder during thedownward stroke of said punch and said outer cylinder, said check valvemeans serving to trap liquid within the lower end of said outer cylinderduring the upward stroke of said punch whereby said piston member andthe ejector plunger connected thereto will be forced upwardly to eject acompacted mass out of said bore, powder loading means including powderdelivery tube means; powder receiving means adapted to be shiftablypositioned beneath said powder delivery tube means to receive a chargeof powder therefrom; and crank synchronized means to shift said powderreceiving means from beneath said powder delivery tube means to passover and center on said die bore after a compacted mass has been ejectedtherefrom, a valve device actuable when said powder loading device hasbeen moved over the top of said bore for 1 1O permitting liquid to flowfrom the bottom of said outer cylinder to said reservoir whereby thepiston member and ejector plunger will move downwardly to fill said borewith a new charge of powder to be compacted, and air cylinder meansinterposed between said piston member and said reciprocable die wherebythe die may move downwardly upon the downward stroke or" the punch whilecompressing the air within said air cylinders, said air cylindersserving to return the die to its uppermost position upon the upwardstroke of said punch.

5. A compacting press as claimed in claim 1 including means forlubricating the walls of said bore after each compacting cyclecomprising an axially-extending passageway in said ejector plunger,radial holes extending between said passageway and the outer peripheralsurface of the plunger, and means for forcing a lubricant into saidpassageway and out through said holes after the plunger has ejected acompacted mass from the bore, the arrangement being such that when theplunger retracts from said one end of the bore preparatory to asucceeding compacting operation it will wipe the lubricant onto the wallof the die bore.

6. A compacting press as claimed in claim 5 wherein said radial holesare provided at the end of the plunger which extends into said other endof the bore.

7. A compacting press as claimed in claim 1 including a mandrel axiallyslideable within said plunger and extending into said bore, means forlubricating the walls of said bore and said mandrel after eachcompacting cycle comprising an annular chamber formed in said plungerand surrounding said mandrel, radial holes extending between saidannular passageway and the outer peripheral surface of the plunger, andmeans for forcing a lubricant into said passageway and out through saidholes after the plunger has ejected a compacted mass from the bore, thearrangement being such that when the plunger retracts from said one endof the bore preparatory to a succeeding compacting cycle it will wipethe lubricant onto the surfaces of said bore and said mandrel.

References Cited in the file of this patent UNITED STATES PATENTS384,872 Simpson June 19, 1888 523,797 Leonhardt July 31, 1894 994,349Updegraff June 6, 1911 1,339,712 Pauley May 11, 1920 2,398,227 HubbertApr. 9, 1946 2,449,257 Tucker Sept. 14, 1948 2,509,786 Richardson May30', 1950 2,556,951 Weidner June 12, 1951 2,651,180 Haller Sept. 8, 19532,810,929 Willi Oct. 29, 1957 2,825,092 Hatch et a1. Mar. 4, -8

1. A COMPACTING PRESS FOR METAL POWDERS AND THE LIKE COMPRISING AVERTICALLY RECIPROCABLE DIE HAVING A VERTICAL BORE EXTENDINGTHERETHROUGH FOR THE RECEPTION OF A POWDER TO BE COMPACTED, A VERTICALLYRECIPROCABLE PUNCH ADAPTED TO BE FORCED INTO THE UPPER END OF SAID BORE,AN EJECTOR PLUNGER HAVING ITS UPPER END EXTENDING INTO THE LOWER END OFSAID BORE TO PROVIDE A BOTTOM SURFACE AGAINST WHICH POWDER IS COMPACTED,MEANS FOR LIMITING DOWNWARD MOVEMENT OF THE EJECTOR PLUNGER BEYOND APOINT WHERE ITS UPPER END EXTENDS INTO THE BORE, HYDRAULIC CYLINDERMEANS FOR MOVING SAID EJECTOR PLUNGER UPWARDLY FROM SAID POINT INTO THEBORE AT THE COMPLETION OF A COMPACTING OPERATION TO FORCE A COMPACTEDMASS OUT OF THE TOP OF THE BORE, SAID HYDRAULIC CYLINDER MEANS HAVING ANOUTER CYLINDER CLOSED AT ITS BOTTOM AND OPEN AT ITS TOP, MEANSCONNECTING SAID OUTER CYLINDER TO SAID PUNCH WHEREBY IT WILL RECIPROCATEWITH THE PUNCH, A PISTON MEMBER RECEIVED WITHIN THE OPEN TOP END OF SAIDOUTER CYLINDER AND RECIPROCABLE THEREIN ABOVE A COLUMN OF SUBSTANTIALLYNONCOMPRESSIBLE FLUID, MEANS CONNECTING SAID PISTON MEMBER TO THEEJECTOR PLUNGER, MEANS FOR INCREASING THE VOLUME OF SAID COLUMN OFNON-COMPRESSIBLE FLUID WHEN THE PUNCH AND OUTER CYLINDER MOVEDOWNWARDLY, MEANS FOR PREVENTING THE VOLUME OF SAID COLUMN OFNON-COMPRESSIBLE FLUID FROM DECREASING WHEN SAID PUNCH AND OUTERCYLINDER MOVE UPWARDLY, AND MEANS INCLUDING TELESCOPING CYLINDERSCONTAINING A COMPRESSIBLE FLUID CONNECTING SAID PISTON MEMBER TO THEDIE.